I recently purchased a second hand 300mm f/4 AF lens, so far it's been great and the results have been excellent.

Next week I'll be driving out to the annual Spruce Woods Star Party in southern Manitoba, and was hoping to take some M31 shots, but I'm at a loss of where to begin.

I'm familiar with the concept of stacking images, and lights, darks and flats. That being said though, I'm clueless of how many would be an appropriate amount, how to stack them, and what settings to use for the best result possible. I'd be shooting in pretty dark conditions, with little to no light pollution (the nearest city is at least an hour and a half drive). Would you recommend shooting wide open, and what would be an ideal ISO? How many shots of what length would you recommend?

I was thinking about 15 lights and 5 darks of 1 minute each, at ISO 1600 at f/4 (piggy back). Would this product acceptable results?

For starters, I'd try the lens wide open. 1 minute should show something assuming the background is dark enough. ISO1600 is reasonable. When you start, take test shots and see how it goes, and don't be afraid to adapt as necessary. If you can afford longer exposures, that's worth a try. Individual exposure length gets you more faint stuff. More exposures help reduce the noise. If you're going to do darks, take at least 10 otherwise you're potentially adding noise. If you feel you're getting enough light, you can stop down if that helps with the lens performance, but be aware if the aperture isn't round, you will get diffraction spikes around stars.

From random notes I tried f/2 ISO1600 in the past, sample results at viewtopic.php?f=22&t=28479Note they're processed somewhat heavily due to light pollution. Without that, you should have a much easier time of it than I did.